Protecting device for power condensers



Sept. 9, 1958 B. HANssoN ET AL 2,851,557

PROTECTING DEVICE FOR POWER CONDENSERS Filed June 2, 1953 d 5 W WM W N fd w mokh V w md Mn mm QZW rZ m m/ Bflmfi T 9 5 Unite rates PatentPROTECTHNG DEVEQE FOR POWER CONDENSERS Bror Hansson, Angby, Berti! C.Zetterstedt, Stockholm, and Thore D. Lintlholm, Hagersten, Sweden,assignors to Allmiinna Svenska Elektriska Aktiebolaget, Vasteras,Sweden, a Swedish corporation Application June 2, 1953, Serial No.359,144

3 Claims. (Cl. 200-125) Power condensers generally consist of aplurality of condenser elements or condenser rolls which are enclosed ina common liquid container and connected to terminals common for all ofthem. In order to limit the effect of short circuits which may be causedby faults in the insulating layers of the condensers, fuses have beeninserted in the connections between the elements and the commonterminals. These fuse wires have either been surrounded by small paperpipes or been inserted in the condenser elements. In both cases it mayhappen that the arc appearing when a fuse wire is molten can damage anadjacent fuse or an adjacent condenser element.

The present invention concerns an arrangement in power condensersconsisting of a plurality of condenser elements with fuses for thedifferent elements in which the difierent fuse wires are enclosed andeffectively separated from each other so that the are appearing when afuse wire is molten cannot have any damaging effect on fuses orcondenser elements in the neighbourhood or damage the insulating liquidin the condenser container. According to the invention all fuse wiresare impressed in a block of insulating material, for instance asbestos,pulp or paper impregnated with some synthetic resin. One end of theconnections between the condenser elements and the fuses as well as oneend of the common terminals are also impressed in said block.

The invention is of special importance in condensers insulated by meansof a chlorinated insulating liquid, for instance chlorinated difenyl,because by the invention it is ensured that the arc formed at the fuseshas no opportunity to disintegrate the said liquid and thus develophydrochloric acid, which, if formed and distributed in the condenser,could decrease its dielectric strength. According to the inventiontherefore the porous material enclosing the fuses may be impregnatedwith some material preventing it from taking up the insulating liquidfor the condenser, for instance some synthetic resin, or the porousmaterial can be mixed up with some material which effectively combineswith the liberated hydrochloric acid.

Patented Sept. 9, 1958 ice The fuse block according to the invention mayfor instance be manufactured so that the connections and fuse wires areinserted between two plates of porous material, which then are pressedtogether, and a binder may then be inserted between them. The porousmaterial may be impregnated with some synthetic resin, which after thecompression of the material is baked. The porous material may be porouspaper, pulp or plates of asbestos or some material of that kind.

Fig. 1 shows a cross sectional view taken along line AA of Fig. 2 and;

Fig. 2 shows the connections made at the fuses of the composite fuseblock.

The accompanying drawing shows a fuse block according to the invention.On the drawing 1 designates two thin plates of paper pulp and 2 theconnections to the condenser elements, 3 the fuse Wires and 4 theterminal common to all condenser elements.

We claim as our invention:

1. A multipolar fuse block for an electric power condenser, comprising astrip of insulating material, a plurality of fuse wires embedded in saidstrip and serving as individual and separate fuses arranged at asutficiently insulating distance from each other, connections located insaid strip and individually projecting outwardly therefrom and allconnected individually each to one end of one of said fuse wires, and aterminal connected to the opposite ends of said fuse wires and alsoprojecting outwardly from said strip.

2. A multipolar fuse block according to claim 1, in which the saidinsulating strip is formed of porous material impregnated with asynthetic resin.

3. A multipolar fuse block, according to claim 1, in which the saidinsulating material is formed by a pair of thin plates of insulatingmaterial tightly joined to each other and said fuse wires being entirelyinterposed between said plates.

References Cited in the file of this patent UNITED STATES PATENTS497,680 Nordmann May 16, 1893 871,851 Young Nov. 26, 1907 1,914,871Siampos June 20, 1933 2,282,849 Beyer May 12, 1942 2,550,119 Marbury etal. Apr. 24, 1951 2,704,341 Stacy et al Mar. 15, 1955 FOREIGN PATENTS667,397 France June 10, 1929 723,820 Germany Aug. 11, 1942 869,987Germany Mar. 9, 1953

